Balamuthia mandrillaris is a free-living leptomyxid amoeba which is known to cause amoebiasis in humans,[1] especially the deadly neurological condition known as granulomatous amoebic encephalitis (GAE). Balamuthia has not been definitively isolated in nature, but it is believed to be distributed throughout the temperate regions of the world. This is supported somewhat by the presence of antibodies to Balamuthia present in healthy individuals. The Balamuthia genus is named in honor of the late Professor William Balamuth for his contributions to the studies of parasitic and free-living amoebas. http://en.wikipedia.org/wiki/Balamuthia_mandrillaris

CDC reports the first known transmission of a rare brain infection, Balamuthia granulomatous amebic encephalitis (GAE), through organ transplantation. The organ donor died of encephalitis that was initially thought to be non-transmissible. Among the four recipients of organs from this donor, two became ill with one dying and the two other recipients remain well. These cases illustrate the risk of transmitting undetected infections via organ transplantation, especially when the cause of death in the organ donor is not clearly defined. Physicians and transplant centers should be aware of the possibility of undetected infections (such as GAE) in potential organ donors, and should avoid using organs from potential donors who die of encephalitis of uncertain origin. Organ procurement organizations should carefully consider the medical suitability of potential organ donors with encephalitis of uncertain etiology. Furthermore, transplant centers should avoid transplantation of organs from these donors, whose organs might pose an elevated risk for fatal infection in recipients.http://www.cdc.gov/media/mmwrnews/2010/n100916.htm#1

We present a case of 23-year-old man with acute meningoencephalitis, accompanied by inflammation of a nasal ulcer. He had been healthy until six months prior to admission to the hospital when he had a motorcycle accident. A star-shaped wound at his nose was incurred after falling into a swamp. A computed tomogram of the brain showed two nonenhancing hypodense lesions at the left caudate nucleus and the right parietal lobe, ependymitis and leptomeningeal enhancement. A skin biopsy showed chronic noncaseous granulomatous inflammation without demonstrated microorganisms. The patient did not respond to the empirical treatment with cloxacillin, ceftriaxone, and amphotericin B, and eventually died on the thirteenth day of hospitalization. At autopsy, hematoxylin and eosin–stained brain sections showed a chronic necrotizing inflammation with numerous amebic trophozoites and rare cysts. Definitive identification of Balamuthia mandrillaris was made by fluorescent immunohistochemical analysis. There were 10 Naegleria fowleri primary amebic meningoencephalitis, eight Acanthamoeba granulomatous amebic encephalitis, and three Acanthamoeba meningitis in Thailand. To our knowledge, this case is the first reported case of B. mandrillaris in Southeast Asia.http://www.ajtmh.org/cgi/content/full/70/6/666

To the Editor: Balamuthia mandrillaris, a free-living soil ameba, can cause granulomatous amebic encephalitis as well as nasopharyngeal, cutaneous, and disseminated infections in humans, nonhuman primates, and other animals. Approximately 100 published and unpublished cases of Balamuthia amebic encephalitis (BAE) have been reported; most were fatal. Diagnosis of BAE is usually made at autopsy, and rarely by biopsy, in part because the amebas can be overlooked in histopathologic preparations. In recognizing BAE as a type of encephalitis that might otherwise be undiagnosed, the California Encephalitis Project (1) has been screening selected serum samples from patients with encephalitis for evidence of antibodies to Balamuthia.

We describe cases of BAE in California and compare data with national data collected on Balamuthia infections since the discovery of the organism in 1990. Since 1998, serum and other samples (cerebrospinal fluid [CSF], throat and rectal swabs, brain tissue) from patients with encephalitis have been submitted to the California Encephalitis Project by participating physicians throughout California. The goal of the California Encephalitis Project is to provide enhanced diagnostic testing for etiologic agents of encephalitis through an intensive testing algorithm. The case definition of encephalitis is encephalopathy, plus one or more of the following: fever, seizures, focal neurologic findings, CSF pleocytosis, or electroencephalographic or neuroimaging findings consistent with encephalitis (1). Persons with HIV/AIDS, severely immunocompromised patients, and patients <6 months of age are excluded from the project.http://www.cdc.gov/ncidod/eid/vol10no8/04-0139.htm

ATLANTA — U.S. health officials say two Arizona organ transplant recipients died of an infection from a microscopic parasite they got from their organ donor.

The deaths are the second confirmed cluster of tranplant-related encephalitis caused by Balamuthia mandrillaris, an amoeba found in soil. It is especially dangerous to people undergoing organ transplants and who have weakened immune systems. The first cluster occurred in Mississippi last year.